Apparatus for conveying material in bulk



Nov. 28, 1961 K. J. SYLVEST 3,010,218

APPARATUS FOR CONVEYING MATERIAL IN BULK Filed Nov. 4, 1958 5 Sheets-Sheet l IN ENTOR g gag/L 114 i025 6 m 7 41 ATTORNEY Nov. 28, 1961 K. .1. SYLVEST APPARATUS FOR CONVEYING MATERIAL IN BULK 3 Sheets-Sheet 2 Filed Nov. 4, 1958 hum/v Nov. 28, 1961 K. J. SYLVEST APPARATUS FOR CONVEYING MATERIAL IN BULK 3 Sheets-Sheet 3 Filed Nov. 4, 1958 INVENTOR fa; 248/ jm gmwf ATTORNEYf' United States Patent Office 3 10,218 Patented Nov. 28, 1961 3,010,218 APPARATUS FOR CONVEYING MATERIAL 11 HULK Karl Jens Sylvest, C'openhagen-Valby, Denmark, assignor, by mesne assignments, to F. L. Smidth & Co., New York, N.Y., a corporation of Delaware Filed Nov. 4, 1958, Ser. No. 771,824 Claims priority, application Great Britain Nov. 11, 1957 Claims. (Cl. 34-164) This invention relates to apparatus, by means of which material in bulk can be conveyed and simultaneously subjected to a chemical or physical treatment by passing a gas through it. More particularly, the invention is concerned with a conveying apparatus, in which the material is advanced over a pervious stationary support by reciprocating conveying elements, the support having openings permitting a gas to pass through the support and into the material but preventing passage of the material, while the elements are wedge-shaped and advance the material during their forward stroke and slide beneath the material on the return stroke. The apparatus is thus generally similar to those disclosed in the patcuts to Nielsen 2,498,218, 2,743,006, and 2,743,007, but differs from the Nielsen conveyors in the provision of novel features overcoming objections to the prior conveyors.

In the prior conveyors, the pervious support, on which the material is conveyed, is made up of a plurality of bearing members separated by grates having openings for the passage of gas and the grates may be formed to check the return movement of the material. The conveying elements rest upon flat surfaces on the bearing members and are connected through openings through the members to driving means beneath the support. Such driving means include a rigid unitary frame structure extending throughout the length of the support and resting upon rollers, the structure being reciprocated by suit able means. The connections between the conveying ele-' ments and the driving means include springs which hold theelements tightly against the bearing surfaces in order to prevent particles of material from entering between the elements and the surfaces and causing wear.

Experience with the prior conveyors has shown that, even though the conveying elements are forced against the bearing members by strong springs, particles of material enter between the opposed surfaces of the elements and members and cause wear, which is heavy when the particles are of an abrasive material. Also, it has been found that, when the material being conveyed is initially at a high temperature, as, for example, clinker issuing from a cement kiln, and is to be cooled as it is conveyed, the use of a single unitary frame structure to which the connecting elements are connected, gives rise to difiiculties because of thermal expansion and warping resulting therefrom.

The present invention is, accordingly, directed to the provision of a conveyor of the stated type, which includes an improved and simplified support and a novel mounting and driving mechanism for the conveying elements which eliminate wear between the elements and bearing surfaces therefor and avoid troubles arising from thermal expansion of parts of the driving mechanism.

For a better understanding of the invention, reference may be made to the accompanying drawings, in which FIG. 1 is a longitudinal vertical section through a cooling apparatus, in which the new conveyor is employed;

FIG. 2 is a sectional view on the line 22 of FIG. 1;

FIG. 3 is a sectional view on the line 3-3 of FIG. 2;

FIG. 4 is a sectional view on the line 44 of FIG. 1 with parts removed; and

FIGS. 5, 6 and 7 are fragmentary plan views showing different forms of the conveyor support.

The apparatus illustrated is for the cooling of hot burned material, such .as cement clinker, discharging from a kiln andv it includes a chamber 10, the upper part of which is lined with refractory material 11. The chamber has an inlet 12 through its top at one end to which a chute 13 for the clinker leads from the kiln, and the air for cooling is introduced through an inlet 14 leading to the interior of the chamber near its bottom at the other end. The air, which has been used for cooling and is heated in the operation, may pass up through the chute 13 into the kiln to be used for combustion but, if the amount of air used for cooling is more than is required in the kiln, the excess air may be permitted to escape through an opening 15 through the wall of the upper part of the chamber near the end remote from the material inlet 12.

The chamber contains a generally horizontal stationary support over which the material is advanced, and the support comprises a plurality of rectangular grates arranged in longitudinal rows with their side edges close to the edges of grates in adjacent rows. The grates may take different forms and each grate 16 (FIG. 5) has flat transverse areas 17, 18 at its ends and an intermediate transverse area 19 which is raised above the flat surfaces and has a steep forward surface 19a facing in the direction of the movement of the material and a rear surface sloping gradually in the direction of the oncoming material. The area 19 of each grate isprov-ided with longitudinal slots 20 which are wide enough to permit the passage of cool air but too narrow to perrnit any substantial amount of the material being conveyed from falling through them. The grates 16 are formed with recesses 21 in their end edges and the recesses of adjacent grates provide openings 21:2 for the connections by which the conveyor elements are driven.

Instead of providing the openings through the support by forming the grates with recesses in their endedges, the openings may be made by forming the grates 16' with narrower flat portions 17', 18' at their ends and mounting the adjacent grates in the longitudinal rows. so that there are spaces 22 between the front edge of one grate and the rear edge of the adjacentgrate in the row. In an alternative construction, the grates 16" are formed without any substantial flat areasat their ends and a flat plate 23 with an opening 23a is placed-between each two adjacent grates 16" in eachlongitudinal row. In all forms of the support, the grates and the plates 23, when used, are mounted on I-beams 24 extending lengthwise of the support and spaced apart by a distance equal to the width of the grates. The beams 24 are supported in any convenient manner and, to allow for thermal expansion, the beams may be divided longitudinally into sections, the ends of which are supported on transverse beams suitably supported at their ends.

The hot material entering the cooler through the inlet 13 falls upon the support beneath the inlet and is ad vanced over the support by reciprocating conveyor elements 25 disposed above respective openings through the support, such as the openings 21a. Each element is of wedge shape and has a steep front surface 26 facing in the direction of movement'of the material and a top surface 27 sloping down gradually to the rear toward the oncoming material. The top surface of each element is formed with a double row of air slots 28 and each element has a pair of projections 29 extending downward from its under surface between the slots and resting on and formed to mate with projections 30 on the tops of girders 31, 32 aligned in pairs extending lengthwise of the support. The projections 29, 30 beneath each conveying element 25 are secured together by bolts 3 33 and extend through an opening, such as the openings 21a, 22, or 23a, through the support. Each element overlies the flat surfaces on thesupport at the opposite ends of the openings.

The forward girders 32 of the aligned pairs are mounted on a rigid frame structure consisting of longitudinal girders 34 and transverse girders 3'5 and the rear girders 31 of the pairs are similarly mounted on a rigid frame structure made up of longitudinal girders similar to girders 34, 35. The frames are provided with lateral projections 36 at their remote ends carrying rails 37 on their under surfaces and the rails rest on rollers 38 on shafts 39 supported in bearings 40 mounted on the side walls of the chamber 10. The adjacent ends of the frames are provided with pairs of links 41, 42 which are connected by a transverse pin 43 which projects through slotted openings in the side walls of the chamber and carries rollers 44 outside the chamber and resting on rails 45.

A sleeve 46 encircles the pin 43 near each end outside the chamber and each sleeve is connected by a connecting rod 47 to a sleeve 48 surrounding an eccentric disc 49 mounted within a housing 50 on a driven shaft 51 in bearings on the walls of the housing. Each shaft 51 carries a gear 52 Within its housing 50 and the gears mesh with respective pinions 53 on a drive shaft 54 Which extends across the chamber and is driven by any suitable means. As shaft 54 rotates, it drives shafts 51, and the rotation of the eccentric discs 49 causes the pin 43 to reciprocate lengthwise of its supporting rails 45 and to reciprocate the frames and conveying elements correspondingly. The length of the stroke of the pin is such that the conveying elements always overlap the portions of the stationary support defining the openings through which the mating projections 29, 30 extend.

In the operation of the apparatus, the material is pushed over the support by the reciprocating conveying elements 25 and is prevented from moving back on the return stroke of the elements by the raised areas 19 on the grates; During its travel along the support, air passing upward through the support and the bed of material thereon cools the material and, at the end of thesupport, the material passes over a solid plate 55 and onto an inclined grate. 56. Oversize lumps of material collecting on grate 56 are removed through a door in the end wall of the chamber above the grate and the fine fraction passing through the grate lands upon a grate 57. The material, which cannot pass through grate 57, is discharged through an outlet 58, while the fine material passing through the grate 57 is discharged through the outlet 59.

As shown in FIG. 3, the conveying elements 25 have flat bottom surfaces and the mating projections 29 on the elements and 30 on the supporting girders 31, 32 are of such dimensions that the bottom surfaces of the elements lie parallel and close to the flatsurfaces of the support, such as the surfaces 17, 18 at opposite ends of the openings 21a through which the projections 29, 30 extend. The bottom surfaces of the elements 25 and the top surfaces of the support beneath the elements accordingly define horizontal slots 60, through 'which the cooling air enters the bed of material being conveyed. The flow of air through the slots prevents the accumulation of material between the support and the conveying elements and the opposed surfaces of the support and elements are constantly kept clean so that wear is avoided.

Although the frame structures, on which the conveying elements are mounted, are rigid, the structures are pivotally connected through the pin 41 and are supported only by the pin at their adjacent ends and by the rollers 38 at their remote ends. 'With this construction, the frames provide proper support for the elements and, at the same time, operating difficulties arising from unequal expansion and inaccurate mounting, when a single rigid frame is used, are avoided.

I claim:

1. Apparatus for conveying material in bulk, which comprises a generally horizontal stationary gas-pervious support'having openings through it in longitudinal rows and means between adjacent openings in each row for checking return movement of material being conveyed, the support having flat top surfaces at the forward and rear ends of the openings, conveying elements of wedge shape disposed above respective openings and having fiat bottom surfaces, a pair of longitudinally aligned rigid frames beneath the support, co-operating means on the elements and frames extending through the openings for supporting the elements on the frame with the fiat bottom surfaces of the elements overlying and spaced from the flat top surfaces of the support, the flat bottom surfaces of the elements and the fiat top surfaces of the support co-operating to define horizontal slots, means engaging the elements and frames for holding the co-operating means in operative relation, means including a horizontal pivot for connecting the adjacent ends of the frames, means supporting the pivot for movement parallel to and lengthwise of the support, means for supporting the remote ends of the frames for movement parallel to and lengthwise of the support, and means connected to the frames for reciprocating the frames and elements lengthwise of the support.

2. The apparatus of claim 1, in which the support is made of a plurality of grates and the checking means are raised portions of respective grates, said portions being of wedge shape and having openings for passage of air.

3. The apparatus of claim 2,v in which the grates are disposed in longitudinal rows with the side edges of the grates in adjacent rows lying close together.

4; In apparatus for conveying material in bulk comprising a support for the material having spaced openings, the combination of conveying elements reciprocable lengthwise of the support to advance the material, a pair of rigid frames disposed in alignment lengthwise of and beneath the support, means including a horizontal pivot for connecting the adjacent ends of the frames, co-operating means on'the elements and frames extending through the openings for holding the elements spaced above the top surface of the support, means for connecting the elements rigidly to respective frames, separate means supporting the pivot and the remote ends of the frames for movement parallel to the support, and means for reciprocating the frames on their supporting means.

5. The combination of claim 4, in which the adjacent ends of the frames are provided with links, a transverse rod connects the links and serves as a pivot, and the reciprocating means is connected to the rod.

References Cited in thefile of this patent UNITED STATES PATENTS 

